Quoting Andrew Perrin <clists@perrin.socsci.unc.edu>:
> This morning I upgraded the kernel on my Sony Vaio PCG-Z505HS from 2.4.20
> to 2.4.22. Everything went very smoothly, until I rebooted the machine --
> at which point it seemed to begin fine, then tried the fsck on /dev/hda4
> which holds / . fsck says "bad superblock" and drops into single-user
> mode with an instruction to fix the problem manually and reboot. Oddly
> enough, though, even fdisk /dev/hda says "Unable to open /dev/hda" -- so
> the block device itself isn't visible, even though that's the device that
> was booted from.
>
try "fsck /dev/hda4". hda is a drive. You can't fsck a drive, only a
partition with a filesystem. hda4 is a partition, hopefully with a
filesystem still on it.
HTH,
Jeffrey